Innovation rate and population structure moderate the effect of population size on cumulative technological culture

Cumulative technological culture is defined as the increase in efficiency and complexity of tools and techniques over generations that allowed humans to conquer the whole Earth. While one part of the puzzling ability of humans to develop such a form of culture lies in their cognitive capacities giving rise to reliable transmission of information, another lies in the impact of demographic factors. Indeed, many studies have examined the impact of population size, innovation rate and population structure on cumulative technological culture. Here, we present a computational model based on a previous model of micro-society that we extended to study the impact of population size and the influence of innovations on cumulative technological culture. Our results showed that population size exhibits an influence on cumulative technological culture, principally in small-scale populations. Additionally, the model suggests that the innovation rate constrains cumulative technological culture and the importance of population size. Indeed, when innovations are frequent, the impact of population size is diminished. Furthermore, our results demonstrate that individuals rely more on themselves than on others to innovate in earlier generations as well as in small populations. However, when populations grow as well as in later stages of evolution, reliance on innovation from others increases. Overall, these results indicate that population size has a limited impact on cumulative technological culture and that other demographic factors such as innovation rate could offer a viable alternative explanation for archeological records.

Alexandre Bluet, François Osiurak, Emanuelle Reynaud